Induction of chromosome aberrations in cultured human cells by ethylenimine and its relation to cell cycle

Sister-chromatid exchanges and chromosomal aberrations in lymphocytes of male albino rats treated with an alkylating agent, apholate (NSC 26, 812; ENT 26, 316)

A lymphocyte culture system was used to study the frequency of chromosomal aberrations and SCEs at various time intervals after an intraperitoneal injection of apholate (0.5 mg/kg b.w.) in male albino rats. Treatment with apholate increased the frequency of chromosomal aberrations significantly (P less than 0.001). The majority of chromosomal aberrations were single chromatid breaks, although other aberrations were also present. The distribution of chromatid breaks was non-random and the large chromosomes were affected to a greater extent. SCEs frequency in lymphocytes of apholate-treated rats was more than 5-fold higher in comparison to controls. The highest number of chromosomal aberrations and SCEs/rat was recorded at 48 h post-treatment, after which there was a gradual decline in both SCE and chromosomal aberration frequency. The results indicate that apholate is a mutagenic compound and it may also be carcinogenic.

Chromosomal aberrations induced by ethylene oxide in a human amniotic cell line in vitro

Ethylene oxide was found to be a potent inducer of chromatid-type aberrations in a human amniotic cell line. This induction was dose-dependent. At doses corresponding to about 9% survival, the number of chromatid exchanges was increased about 20 times, and the number of induced breaks increased 50 times, above that observed in the controls.

Mammalian in vivo and in vitro cytogenetic assays: a report of the U.S. EPA's gene-tox program

This report presents an assessment made by the U.S. Environmental Protection Agency Gene-Tox Program's Work Group on mammalian cytogenetics of the clastogenic effects of chemicals in in vivo and in vitro mammalian cell assays. This assessment is based on information provided by the Environmental Mutagen Information Center, Oak Ridge National Laboratory, with the proviso that the experimental protocol used in these papers was adjudged to be acceptable by standards outlined by the Work Group. Some data were accepted as "qualitative only" because the protocol used was fairly close to that proposed as suitable. Using these criteria, 177 papers were selected for review. 6 assays were reviewed: bone marrow (32 papers, 31 chemicals), spermatogonial (10 papers, 10 chemicals), spermatocyte (25 papers, 25 chemicals), oocyte or early embryo (18 papers, 19 chemicals), in vitro cell culture (30 papers, 66 chemicals), and leukocyte (66 papers, 53 chemicals). Each assay was considered separately, and comparisons were then made between them for their similarities or differences in producing a positive or negative clastogenic effect of a particular chemical or chemical class. A large proportion of the available cytogenetic data was not suitable for inclusion in the final data base because of poor experimental design or unsatisfactory reporting of the information. It was not possible to recommend any one assay for determining potential clastogenicity because each had its own particular advantages and limitations and provided unique information. For demonstrating in vivo effects, the bone-marrow assay is probably the simplest and most economical. If only in vitro exposures were considered, leukocytes or cultured mammalian cell lines would be suitable. However, there are advantages to using leukocytes because they are a synchronous population, at least through their cell division, and because of the ready availability of human cells. In general, there was good agreement between clastogenicity and carcinogenicity.

Potential carcinogenic and mutagenic industrial chemicals. I. Alkylating agents

A variety of alkylating agents, acylating agents, peroxides, halogenated derivatives, and nitrogen derivatives have been reviewed, principally in terms of their synthesis, areas of utility, stability, distribution, reactivity, levels of exposure, population at risk, metabolism, carcinogenicity, and mutagenicity.

Effect of two chemosterilants apholate and hempa on the bone-marrow chromosomes of mice

Mice were injected with 0.1% solution of apholate and hempa at the rate of 1.5 ml per 100 gm body weight and their bone-marrow cells were fixed at different intervals between 15 min and 144 hr. Specimens injected with distilled water served as controls.Only three aberrations were found in 4,100 metaphases in the control series. In the hempa-treated series, out of 4,100 metaphases examined one chromatid break, one subchromatid break, two gaps and one exchange were found at 24 hr only.In the apholate-treated series aberrations were absent only at 15 min and 144 hr post injection. At other times the aberrations were single chromatid breaks, subchromatid breaks, aniso- and isochromatid breaks, constrictions, gaps and lesions and exchanges. The aberration peak of 28.2% was reached at 24 hr, and fell to 0.3% at 120 hr. The breaks were non-randomly distributed between and within chromosome groups. Groups I and II and distal region of all affected groups were most susceptible.The mode of action of apholate and hempa in the induction of chromatid aberrations in mice, their localization and non-random distribution are discussed. The role of the aziridine groups in inducing aberrations has been considered. It is suggested that the breaks were due to some direct action and that the chromatids of mice contain some weaker regions.